The invention relates to a baling press with a rope tying system and to a method of supplying rope to a knotter of a baling press.
Knotting mechanisms for tying a rope around a bale pressed in a baling press have been known for more than a century. Compared with tying bales with steel or plastic wire material, tying bales with rope provides the advantage that a wider range of generally lower cost materials are available and that in rope material is generally more robust in practice, since a smaller reduction of the tensile strength is caused by knots and sharp bends. A particularly well-known knotter is the Appleby knotter, which allows mechanical knotting of twined rope material. Such a knotter is disclosed in U.S. Pat. Nos. 208,137, 591,614 and 744,153. More recent applications of knotters of this type in baling presses are disclosed in German patent specification 27 59 976 and European patent application 1 190 618. Such knotters have been developed for and are widely applied in the field of harvesting machines for tying bales of hay and straw.
In such baling presses, the knotter is arranged at a first side of a bale pressing channel and a first rope material is fed at the first side of the bale pressing channel. A second rope material is fed at the second side of the bale pressing channel opposite of the first side. Each time a bale has been pressed, a loop supply arm is moved from the second side of the bale pressing channel to the first side along a trailing face of the pressed bale and forming and supplying a loop of the second rope material to the first side of the bale pressing channel, where the second rope material and the first rope material are engaged in a knotting area and knotted together by the knotter, thereby closing a loop of the first and the second rope material at the trailing end of the pressed bale. The formed knot is then cut off the more upstream rope material, of which free ends are held at the knotter. The loop supply arm is then retracted and a section of the first rope material is pressed towards a section of the second rope material extending through knotting area, where the first rope material and the second rope material are again engaged in the knotting area and knotted together by the knotter, thereby starting a loop of the first and the second rope material to be formed around the leading end of next bale to be pressed. Thus, sections of the first and the second rope material have to be presented in the knotting area twice, first for forming the knot at the trailing end and subsequently, after the first knot has been cut off from the rope material, for forming the knot at the leading end of the next bale.
The larger a baling press, the more space is required for the loop supply arm at second side of the bale pressing channel and its range of movement. Furthermore, in view of the need of accurately supplying a loop to the knotting area at a side of the bale pressing channel opposite of the side where the loop supply arm is suspended, the loop supply arms need to be of a stiff construction and be manufactured with tight tolerances.